The present invention relates to an image forming apparatus.
As an image forming apparatus, there have so far been provided a copying machine wherein images such as character strings or patterns or a combination thereof described on a document placed on or fed to a platen glass (document glass) are copied on a transfer sheet, a printer wherein images which are made on a word processor of a personal computer and are the same as the foregoing are printed on a transfer sheet, and a facsimile machine wherein images which are transmitted through communication lines and are the same as the foregoing are printed. Further, there is also known the so-called “compound machine” wherein the functions of the aforesaid copying machine, printer and facsimile machine are provided in an apparatus.
Incidentally, with regard to a conventional image forming apparatus, there have been provided those capable of conducting image forming on a transfer sheet (so-called “wide sheet”) that is slightly larger than a standard fixed-form size in terms of area. When conducting image forming on the wide sheet, control conditions for an image forming apparatus have usually been changed to the conditions which are suitable for the wide sheet.
This change of control conditions is necessary because of a size of the wide sheet which is larger than the standard fixed-form size as stated above. The control condition to be changed includes, for example, a control condition for transfer sheet conveyance in an image forming apparatus.
In the past, however, the control conditions used for a wide sheet have not always been optimum. For the conveyance control condition for a wide sheet, for example, a transfer sheet in a “certain size” that is greater than a fixed-form size is imagined, and the conveyance control condition for this “certain size” has been used as a substitute. Namely, in this case, the conveyance control condition for a wide sheet is nothing but one that is prepared as a fixed condition determined in advance.
The wide sheet, however, is not usually fixed in its size, and it varies variously in terms of size. Under the aforesaid fixed condition, therefore, it is not possible to cope with all of these various wide sheets sufficiently and properly. Accordingly, it has been difficult to form images with high quality and to conduct highly productive image forming.
Further, in the conventional image forming apparatus disregarding existence of the aforesaid various wide sheets, no attention has been paid to “setting” which can cope with the diversity mentioned above.